Table 1.
Overview of the different types of EULs and their occurrence in plants.
| Different types of EUL | Plant species | |
|---|---|---|
| Type S: Proteins with a single EUL domain | ||
| Type S0 | Proteins consisting of an EUL domain only | Euonymus europaeus, Plantago major, Zea mays, Selaginella moellendorfii |
| Type S1 | Proteins consisting of an EUL domain preceded by a short (<50 AA) unrelated N-terminal sequence | Physcomitrella patens, Triticum aestivum, Hordeum vulgare, Selaginella moellendorfii |
| Type S2 | Proteins consisting of an EUL domain preceded by a medium long (50-100 AA) unrelated N-terminal sequence. | Oryza sativa, Sorghum bicolor, Zea mays, Lactuca sp., Pinus taeda, Picea sitchensis |
| Type S3 | Proteins consisting of an EUL domain preceded by a long (>100 AA) unrelated N-terminal sequence. | Arabidopsis thaliana, Medicago truncatula, Vitis vinifera, Populus trichocarpa, Oryza sativa, Sorghum bicolor, ... |
| Type S4 | Proteins consisting of a medium long (50-100 AA) unrelated N-terminal sequence, an EUL domain, and a short (<50) C-terminal extension. | Selaginella moellendorfii |
| Type S5a/S5b | Proteins consisting of a short (<50) unrelated N-terminal sequence, an EUL domain, and a short (<50) or medium long (50-100 AA) C-terminal extension. | Marchantia polymorpha |
| Type Sv | Proteins consisting of an EUL domain preceded by a short unrelated N-terminal sequence containing a signal peptide (vacuolar form of the EUL). | Sorghum bicolor, Zea mays, Hordeum vulgare, Triticum aestivum, Selaginella moellendorfii |
| Type D: Proteins with two in tandem arrayed EUL domains | ||
| Type D0 | Proteins consisting of two in tandem arrayed EUL domains separated by a short (<40 AA residues) linker and without N-terminal extension. | Selaginella moellendorfii |
| Type D1 | Proteins consisting of two in tandem arrayed EUL domains separated by a short (<40 AA residues) linker and preceded by a short (15-35 AA residues) N-terminal extension | Oryza sativa, Sorghum bicolor, Zea mays, Hordeum vulgare, Triticum aestivum, Pinus taeda, Picea sitchensis, Physcomitrella patens |
| Type D2 | Proteins consisting of two in tandem arrayed EUL domains separated by a long (>40 AA residues) linker and preceded by a short (10-35 AA residues) N-terminal extension | Oryza sativa, Sorghum bicolor, Zea mays, Hordeum vulgare, Triticum aestivum, Pinus taeda, Picea sitchensis, |
| Type D3 | Proteins consisting of two in tandem arrayed EUL domains separated by a short (<40 AA residues) linker and preceded by a long (>50 AA residues) N-terminal extension | Selaginella moellendorfii |
| Type D4 | Proteins consisting of two in tandem arrayed EUL-related domains separated by a short (<40 AA residues) linker and without N-terminal extension. Note that the domains of these proteins share only low sequence similarity with the genuine EUL domains. | Selaginella moellendorfii |
A schematic overview of the different types is shown in Fig. 1.